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Photochromy
Photochromy is the art or process of reproducing colors by photography.ote/sup> Not to be confused with Photochromism (a reversible color change induced by light energyThe Focal Encyclopedia of Photography, page 1079, Desk Edition (1969), Focal Press, ). See Photochromism. Furthermore, a Photochrom is not the result of the photochromy process. History Colored images by direct exposure from nature using a Lippmann plate Gabriel Lippmann conceived a two-step method to record and reproduce colours, variously known as direct photochromes, interference photochromes, Lippmann photochromes, Photography in natural colours by direct exposure in the camera or the Lippman ... Color printing method by the bleach-out process. Notes In the original publication in 1891, Lippmann reports on photochromy in which he describes his famous method of photography in colors, the so-called "interference" method, based on the action of stationary waves. References {{reflist Photographic processe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Color
Color (American English) or colour (British English) is the visual perceptual property deriving from the spectrum of light interacting with the photoreceptor cells of the eyes. Color categories and physical specifications of color are associated with objects or materials based on their physical properties such as light absorption, reflection, or emission spectra. By defining a color space, colors can be identified numerically by their coordinates. Because perception of color stems from the varying spectral sensitivity of different types of cone cells in the retina to different parts of the spectrum, colors may be defined and quantified by the degree to which they stimulate these cells. These physical or physiological quantifications of color, however, do not fully explain the psychophysical perception of color appearance. Color science includes the perception of color by the eye and brain, the origin of color in materials, color theory in art, and the physics of electr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Photography
Photography is the art, application, and practice of creating durable images by recording light, either electronically by means of an image sensor, or chemically by means of a light-sensitive material such as photographic film. It is employed in many fields of science, manufacturing (e.g., photolithography), and business, as well as its more direct uses for art, film and video production, recreational purposes, hobby, and mass communication. Typically, a lens is used to focus the light reflected or emitted from objects into a real image on the light-sensitive surface inside a camera during a timed exposure. With an electronic image sensor, this produces an electrical charge at each pixel, which is electronically processed and stored in a digital image file for subsequent display or processing. The result with photographic emulsion is an invisible latent image, which is later chemically "developed" into a visible image, either negative or positive, depending on the purp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Photochromism
Photochromism is the reversible transformation of a chemical species (photoswitch) between two forms by the absorption of electromagnetic radiation (photoisomerization), where the two forms have different absorption spectra. In plain language, this can be described as a reversible change of color upon exposure to light. Applications Sunglasses One of the most famous reversible photochromic applications is color changing lenses for sunglasses. The largest limitation in using photochromic technology is that the materials cannot be made stable enough to withstand thousands of hours of outdoor exposure so long-term outdoor applications are not appropriate at this time. The switching speed of photochromic dyes is highly sensitive to the rigidity of the environment around the dye. As a result, they switch most rapidly in solution and slowest in the rigid environment like a polymer lens. In 2005 it was reported that attaching flexible polymers with low glass transition temperature (f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Photochrom
Photochrom, Fotochrom, Photochrome or the Aäc process is a process for producing colorized images from a single black-and-white photographic negative via the direct photographic transfer of the negative onto lithographic printing plates. The process is a photographic variant of chromolithography (color lithography). Because no color information was preserved in the photographic process, the photographer would make detailed notes on the colors within the scene and use the notes to hand paint the negative before transferring the image through colored gels onto the printing plates. History The process was invented in the 1880s by Hans Jakob Schmid (1856–1924), an employee of the Swiss company Orell Gessner Füssli—a printing firm whose history began in the 16th century. Füssli founded the stock company Photochrom Zürich (later Photoglob Zürich AG) as the business vehicle for the commercial exploitation of the process and both Füssli and Photoglob continue to exist today. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lippmann Plate
Gabriel Lippmann conceived a two-step method to record and reproduce colours, variously known as direct photochromes, interference photochromes, Lippmann photochromes, Photography in natural colours by direct exposure in the camera or the Lippmann process of colour photography. Lippmann won the Nobel Prize in Physics for this work in 1908. A Lippmann plate is a clear glass plate (having no anti-halation backing), coated with an almost transparent (very low silver halide content) emulsion of extremely fine grains, typically 0.01 to 0.04 micrometres in diameter. Consequently, Lippmann plates have an extremely high resolving power exceeding 400 lines/mm. Method In Lippmann's method, a glass plate is coated with an ultra fine grain colour-sensitive film using the Albumen Process containing potassium bromide, then dried, sensitized in the silver bath, washed, irrigated with cyanine solution, and dried again. The back of the film is then brought into optical contact with a reflective ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
